Producing power from geothermal heat sources currently is being carried out on a wide scale throughout the world. In many installations, hot geothermal fluid extracted from a production well is flashed into steam in a separator that produces geothermal steam rich in non-condensable gases, such as hydrogen sulfide, carbon dioxide, etc. The brine that remains is sometimes so corrosive, and sometimes contains such a high concentration of silica, that from an engineering standpoint, it must be disposed of in a re-injection well without using a significant amount of heat contained therein.
The geothermal steam produced from the separator is applied to a steam turbine coupled to a generator, the steam expanding in the turbine and driving the generator which produces electricity. Condensing expanded steam in the turbine exhaust is often a problem when an inadequate supply of ambient cooling water is available. Usually, the expanded steam contains noxious gases which, for environmental reasons, precludes the use of an open system condenser, such as cooling towers, for condensing the steam even when ambient water is available. Under such conditions, chemical pre-treatment of the exhaust steam is usually required to suppress escape of the non-condensable gases. This is an expensive, and complex, solution to the problem.
It is therefore an object of the present invention to provide a geothermal power plant and a condenser therefor which is capable of operating without significant amounts of ambient cooling water, and which avoids the problems described above.